The Reciprocity Principle and Social Responsibility Norm Are Both Normative

The reciprocity principle and social responsibility norm are both normative beliefs that may explain why we have a tendency to help others, however, they differ in that:

A) one suggests we only help friends, while the other explains why we help family, friends and strangers.
B) One has empirical support, the other does not.
C) One suggests we help those who help us, while the other suggests we help those .in need regardless of whether they have helped us.
D) One suggests we help those who help us, the other suggests we only help when we will be rewarded for our help.